Machine for molding concrete blocks



Sept; 11, 1951 J. o. CHRISTENSEN MACHINE FOR MOLDING CONCRETE BLOCKS Filed 001;. 51, 1945 8 v k W 5 A 0 5 E E m H w K u ym lnvenzar: \AQEI/ZISTENsz-N,

Patented Sept. 11, 1951 UNITED STATES PATENT OFFICE MACHINE FOR MOLDING CONCRETE BLOCKS J 111 Christensen, ,Las Y New pplication October 31, 1945, Serial No. 625,844

12 Claims. 1 Thi invention relates to a :block machine, and more particularly a machine for forming building plocks of a plastic material such as cinder ene at Among the principal objects of the invention are:

to) To p vide a machi e that is simpl in construction and unencumbered with superfluous fl l finfl t s- ,(b) To provide a construction that facilitates the use of a mold, all par-ts of which, including n core, are stationary and integral one with another. a

(c) To be co nven ient and efficient in operation.

(d) To be capable of producing a maximum output with a minimum expenditure of labor.

(a) To interchangeably receive molds of in? fin te va ety- .(a) To be inexpensive.

(9) To have a well-balanced action.

(it) To be positive and reliable in its action.

Other objects will presently become obvious.

A characteristic .of the invention is the provision of a compactly framed structure on the top of which is supported astationary mold having a selt-contained core, the mold being adapted to receive plastic .cinder concrete directly from a suilpble source of supply.

An elevating pallet is located below the mold sons to have an alternative position where it bears snugly against the bottom of the mold, and another position where the pallet with a load being discharged from the mold, is automatically deposited, without the intervention of any manual exertion other than that imposed on only one operatin lever, on an off-bearing conveyor. The elevating pallet is advantageously balanced and uided, and is preferably actuated by means of geared sector elements having their center of motion along the front of the framework and being suitably interconnected with a system of levers and links, all under the control of the one operating lever disposed within easy reach of an operator standing in front of the machine.

Vibratory elements tor compacting the concrete in the molds are disposed below the elevating mechanism so as to exert the compacting force in a Well-balanced manner centrally of the pallet.

In the accompanying drawing, which illustrates one embodiment of the invention,

Fig. 1 represents a plan, which includes a mold of one type, adjacent auxiliary parts being shown ra ment rilys Fig. 2, a side elevation; v d r: v

Fig. 3, a vertical section taken on the line 3-.-;3 in Fi 1;

Fig. 4, a fragmentary front elevation including however, a mol f n th t p Fig. 5. a pair of finished blocks formed in the molds o F g.

Fig, :,6, a fragmentary view partially in section of the core.

Referring to the drawing, the numeral H] denotes -a framework advantageously comprising the front posts 1-! and the rear posts l2, these posts being suitably connected to the sills 13. top of the frame I0 is supported a multiple mold -;l4 comprisingthe side walls 15 and the end walls [6. Inside the mold [4 are suitably positioned partitions 1-1 which divide the mold into three distinct compartments, each compartment ill having a respective core Hi. In this instance, therefore, the multiple mold is arranged for pro.- ducing three separate blocks during each cycle of opera'tidn. The two cores of each pair are advantageously connected to each other and to the respectiae side walls l5 by means of integral ties 210, these ties being preferably V-shaped in crosssection. Theseties need be only strong enough to hold the cores in position, since they perform no other useful function and it is desirable to make the resulting indentations 2| in the top of the molded blocks as inconspicuous as possible. it is to be observed that the mold I4 represents onlyqone of an infinite number of different pat-.- terns that might be required for producing blocks in diversified building industries. Therefore the mold 14 is made removable from the frame In by, any suitable means, such as flanges 22, which in this example are removably bolted to the frame .l-ll.

Intermittently, that is to say, at such times as blocks are being molded, a pallet 23 is held in contact with the bottom of the mold 14 so as to cover at least partially the open area. thereof, the pallet being supported in the intermittent positions by any suitable means, such as cross.- f rame -24 resting on the respective movable stand.- ards -25. The standards 25 are arranged to slide up and down along the respective stationary guides 26. As illustrated in the present drawing, the respective standards 25 are provided with rack portions 21 that are inter-meshed with the arcuate, toothed portion 28 of the sectors 29, the latter being rig-idly mounted for oscillation on a shaft 30. This shaft extends along the front of the frame t0 and is journaled in the respective bearings 3|. Also rigidly mounted on the shaft 3.01 an arm 32 this am at its swinging d be- 3 ing pivotally connected to a lug 33, the lug in turn being advantageously connected to a rod 34 by means of a threaded portion 35. At the other end of the rod 34 is similarly mounted another lug 36, this lug being advantageously forked and pivoted at 31 to an operating hand lever 38. Thus, the rod 34 with its lugs 33 and 36 constitutes an adjustable link extending from the arm 32 to the lever 38. Finally, the hand lever is connected to the stationary frame It] by means of a fixed pivot 39.

The hand lever 38 with its connected link work, I

as illustrated by the full lines in Fig. 2, is in its lowermost position, but at the same time the gear sector 29 and the sliding standard 25 are in their respective uppermost positions, acting to hold the pallet up against the bottom of the mold.

An important point to observe is that the short arm 40 of the lever 38, between the pivotal points 31 and39, is in substantial alignment with the line joining the pivotal points of the link 34, thus forming an interlock whereby all the movable parts are held securely in the position of the full lines in Fig. 2. In this position the load, which includes the pallet with its appurtenances and the weight of any blocks that may be in process, hangs on the sectors 29. The total load naturally exerts a moment about the axis of the shaft 38, which moment, however, is resisted by the moment of the composite arm formed along the straight line extending from the center point 39 to the pivotal point 4 l. The interlocked position is maintained because the lever 38 rests against the back of the forked lug 36 at the point 42, so that the back of the lug forms a stop, and the weight of the long arm of the lever 38 is a factor in the moment exerted about the center 39. Naturally, if the pivot 31 is located slightly below a straight line from 39 to 4!, the interlock is more secure.

The standards 25 and appurtenances form an elevator.

In operation, the movable parts being in the full line position of Fig. 2, cinder concrete or other like plastic material, supplied from a suitable source (not shown), is delivered directly into the mold l4 by means of chute 43. A hopper-like structure 44 guards against spillage over the top of the mold. After jarring the plastic contents of the mold to a suitable degree of compactness, any small excess is trimmed off flush with the top of the mold. Thi leaves the freshly formed blocks ready to be discharged from the mold by gravity, assisted if necessary, by further slight jarring. The discharge of the blocks commences after the workman grasps the hand grip 48 of the long arm of the lever and starts it upward towards the alternative position indicated by the broken lines 38l. When this position of the lever has been reached, the discharge of the blocks 58 from the mold will have been completed, and further, cross-frame 24 will have been carried down a little farther, for illustration, to the alternative position 24?), Fig. 3, free of the pallet, the latter with its load being left in the alternative position 231), where it is resting on the first rollers 58 of the offbearing conveyor The workman pushes the loaded pallet manually, back out of the way, where the blocks are in the position 58a. Thereupon, another pallet is placed on the cross-frame in the space left vacant under the mold l4, ready to be raised against the bottom of the mold. By pulling down the lever 38 from its alternative position 38l back to its initial full-lined position 38,

4 the apparatus is ready for another cycle of block forming.

The advantageous and compact arrangement of the operating parts just described is made possible because the lever 38 is of the second order, that is to say, the weight is located at 3! between the power at 48 and the fulcrum at 39.

Obviously, the number of blocks formed in each cycle of operation as just described, depends on the particular design of the mold 14. In Figs. 1 and 3, the mold is a three-block type, while in Fig. 4, it is a two-block type 52, from which the blocks 53 have just been discharged upon the pallet 54. In Fig. 5, the two finished blocks are shown just as discharged from the mold, the two blocks being separated from each other by the space 55 left by apartition in the mold. By leaving out partitions a single block of the size of the entire mold could be formed.

In the case of the smaller blocks such as those illustrated at 58, Figs. 3 and 6, only a single line of connecting ties 28, Figs. 1 and 6, is used to support the cores within the molds, butin the case of the larger blocks 53, Fig. 4, two or more lines of supporting ties might be used.

Important novel features of the invention are those that in operation contribute to a modern streamlined performance, this being directed to a pattern-no backtracking to cause lost motion. A feature is the integral design of the mold structure whereby first, a cored block absolutely true to form is produced; and second, the completed block is freely and expeditiousl discharged from the mold without distorting the block.

The novel unobstructing ties 2|, their V-shape and their advantageous, substantially flush disposition at the extreme top of the mold, makes possible the dropping of a block out of the mold by gravity, without interference. At the same time filling of the mold with the plastic mixture is facilitated.

The particular arrangements and sizes of the ties depends on individual circumstances, the significant consideration being the integral relation between core and mold.

The cores, such as l9, are preferably hollow so that atmospheric air is caused to pass underneath the bottom perimeter of the core as the block leaves the mold, thereby preventing the suction that would otherwise occur, from distorting the block by causing a drawing-in action. Air is admitted to the inside of the cores by means of very small holes 51 or slots 56.

The novel mold design, together with the floating interlock of the lever 38, brings about the convenience and simplicity of operation of a machine constructed in accordance with the invention in that a single movement completely frees and discharges the blocks from the mold.

Diiferent molds are easily interchanged one for another by manipulating the fastening means between a mold and the framework on which it is supported.

In Fig. 6 is illustrated the manner in which atmospheric air assists in releasing the molded block from its mold. In this figure the pallet is in a position 23a intermediate the extreme operative positions, where the block 58 is just drawing out of the mold I 4. The arrows indicate air entering from the atmosphere through the relief opening 58 and acting to prevent a suction from being exerted along the lower edges of the mold which otherwise would impede the release of the block and cause a certain deforma tion thereof.

Apparatus for jarring the molds to compact the plastic mass, is illustrated in Fig. 2, where the eccentrically disposed rotatable weights 45 are driven by means of a belt 46 encircling the pulley of a motor 41. It is to be noted that the weights are directly under the center of the molds so as to distribute the compacting forces symmetrically throughout the molds.

Having fully described my invention what I claim is:

1. A plastic-block forming machine comprising a mold; pallet means movable up or down below the mold; and elevator means disposed to raise the pallet into position to at least partially form the bottom of the mold; said elevator means including a toggle-joint construction in which the stressed position of the toggle arms is transverse to the line of travel of the pallet means and at the same time is located between the lower point of travel and the raised point of travel of said pallet means; and means operative to form or to break, as the case may be, the stressed position of the toggle arms.

2. A machine according to claim 1, wherein said means to form or to break the stressed position of the toggle arms comprises an extension of one of said toggle arms and in conjunction therewith constitutes a lever of the second order.

3. A machine according to claim 2, wherein said lever in conjunction with the other of said toggle arms forms an interlock in the stressed position of the toggle arms.

4. A molding machine for plastic material, comprising a mold; a pallet disposed to support plastic contents of the mold; an elevator including a toggle-joint construction having its straightline position wholly intermediate the limits of travel of the pallet; and an extension at the knuckle end of one of the toggle arms, which extension together with its toggle arm constitutes a lever of the second order.

5. A plastic forming machine comprising a frame; a stationary mold supported by the frame; pallet carrying means having vertically disposed tubular supporting members; guides on which the tubular members are slidable; rack portions integral with the tubular members; gear sectors intermeshed With said rack portions; shaft means by which the gear sectors are oscillatingly supported; swinging arm means effective to oscillate the shaft means; multiple linked interlock means having a stationary pivot at one extremity and pivotally connected to the swinging end of the arm means at the other extremity; and lever means of the second order operative to form or to break, as the case may be, the interlock of said interlock means.

6. A molding machine for plastic material, according to claim 4, wherein the mold has fixed walls, an open top and an inverted open box core; ties integrally connecting the core to the mold and so disposed that a plastic formed article rests on the pallet means and is freely dischargeable from the mold by gravity.

7. A molding machine for plastic material according to claim 6, wherein the integral ties between the mold and its core is V-shaped in crosssection; and wherein the top of each tie is flush with the top of the mold and with the top of the core while the vertices of the V-ties point downwardly to aid in the gravity discharge of the formed article.

8. A molding machine, comprising a horizontally disposed mold having its bottom open; a pallet adapted to close the bottom of the mold; an elevator operably arranged below the mold for receiving a pallet and raising it into a position closing the said open bottom of the mold prior to a molding operation and for lowering the said pallet together with the molded article following the molding operation; conveying means extending transversely into the elevator space for receiving and removing the loaded pallet on the down trip of the elevator; and actuating means disposed to operate said elevator, which actuating means includes a toggle-joint construction characterized by the fact that the stressed position of the toggle arms is located intermediate the raised pallet position and the lowered pallet position, and further by the fact that in the stressed toggle-arm position the toggle-arms are locked together to sustain said pallet in the raised mold-closing position.

9. A molding machine for plastic material, comprising a mold; pallet means below the mold, said pallet means having an upper and a lower position; actuating means operative to move said pallet means up or down as the case may be; said actuating means including a toggle-joint construction having its position of stress between the toggle arms intermediate the upper and lower positions of said pallet means and it knuckleposition substantially above the upper position thereof.

10. A molding machine according to claim 1, in which the knuckle-position of said toggle arms is located substantially above the raised point of travel of the pallet means.

11. A molding machine according to claim 4, in which said toggle-joint construction has its knuckle-position substantially above the upper travel limit of said pallet.

12. A molding machine according to claim 8, in which the toggle arms in the knuckle-position thereof, are located substantially above the raised position of the pallet.

JOSEPH O. CHRISTENSEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 64,778 Marshall May 14, 1867 833,701 Strait et a1. Oct. 16, 1906 929,981 Price Aug. 3, 1909 937,885 Sterling Oct. 26, 1909 1,579,042 Watkins Mar. 30, 1926 1,642,980 Turner Sept. 20, 1927 1,754,484 Pelton Apr. 15, 1930 1,905,975 Thomas Apr. 25, 1933 

